The present invention pertains to structures which flex spherical mirrors into precise aspheric shapes and mirror assemblies employing such structures.
In Sky and Telescope magazine, June 1992, one of the present inventors, William Kelley, described a method of pulling a spherical mirror into a rough approximation of a paraboloid with a central stud which was bonded to the back of the mirror.
Others have discussed warping mirrors into asymmetric shapes.
Still others have discussed deforming mirrors during the grinding process, then releasing them after grinding in order to achieve a desired shape.
The present inventors have discovered new methods of flexing spherical mirrors to achieve highly accurate axisymmetric shapes such as paraboloids. These methods involve one or more of the following:
a. Pulling on a large diameter circular area of the mirror back.
b. Pulling on an annular area of the mirror back.
c. Pulling on a mirror with a puller attached to the mirror back via an elastic layer.
d. Pulling on a mirror having a tapered back surface.